by Walter Olson, USA TODAY

by Walter Olson, USA TODAY

Will the Supreme Court rule next year that the Equal Protection Clause of the U.S. Constitution implies a right to gay marriage?

While it's dangerous to make predictions in this fast-evolving area, my guess is: probably not. More likely is a split or narrow decision in one or both of the two cases the Court agreed to hear today.

The Justices today took special care to leave their options open, including the option to decide one or both cases on legal "standing" grounds that would settle nothing of substance.

Of the two cases, the better shot for conservative opponents of gay marriage is Hollingsworth v. Perry, the challenge to California's Proposition 8. The Court's four most conservative justices are considered receptive to an argument that it should be up to California voters to decide whether to recognize same-sex marriage.

Even if Justice Anthony Kennedy sides with the liberals, few will be surprised if he writes an opinion narrowly tailored to the California facts while not creating a more general right to gay marriage.

In the other case the Court agreed to review, Windsor v. U.S., the Second Circuit Court of Appeals struck down Section 3 of the federal Defense of Marriage Act, which defines the word marriage for purposes of all federal laws as solely the union of one man and one woman. (A second part of DOMA, section 2, which provides that states are not obliged to recognize other states' same-sex marriages, is not under challenge.)

Since DOMA was passed during the Clinton administration nine states have extended recognition to same-sex marriages, which means many couples are now married under the law of the state where they live but not federal law. And so it was that the IRS told Edith Windsor that she'd have to pay estate tax on the property left by her partner of 42 years Thea Spyer, to whom she'd been legally married under New York law.

Those aren't exactly the kind of facts that attract public sympathy. DOMA's defenders face several other problems as well. One is that multiple courts have now found the section unconstitutional. A second is that the Windsor opinion itself was penned by Second Circuit chief judge Dennis Jacobs, a leading conservative who's long been highly regarded in Federalist Society circles.

Voters and legislators are changing their minds fast on this issue. But it's unlikely that Congress will amend or repeal DOMA, or Californians vote to reverse Prop 8, in time to avoid the need for the Court to decide.

Walter Olson is senior fellow at the Cato Institute's Center for Constitutional Studies.